In a centrifugal compressor of the prior art, the regulator is installed at the outlet of the impeller, forming a segment with an adjustable width. The outlet width of the impeller is regulated according to the operating conditions of the unit, so as to enable the unit to remain at the highest operating efficiency in a wider range. In the prior art, the regulator of the centrifugal compressor is normally linked with the regulating mechanism of the impeller. The regulator is not independent in structure, and thus the control is not precise enough. What is more, the regulating range of the adjustable width of the impeller is relatively smaller, and the regulator of the centrifugal compressor is not applicable to compressors under various kinds of operating conditions.
In view of the defects above, after long time of research and practice, the inventors finally obtained the present invention.